Jasper,
I don't want to seem rude but if you have been "undertaking fra's at a large number of nursing homes" and don't know the answer to your question, I am surprised that you feel competent.
There is a healthy and at times spirited debate over the respective merits of self-closers, free swing devices, sprinklers, stay put arrangements, staffing levels and horizontal/limited evacuation. All these issues need to be considered.
However, to answer your question, there are no regulations absolutely requiring s/c on bedroom doors and the RRO will definitely not require them either.
Personnaly, I believe sprinklers and compartmentation are the best options, especially if the resisdents are very immobile. Well fitting fire doors and old style self closers generally mean that the residents cannot open their doors unaided.